Pneumatic hammer.



- ter with the inlet ports and thus admit a' JOS-.EPH FREDERICK, OF STROUDSBURG, PENNSYLVANIA.

PNEUMATIC HAMMER.

Np.- 891,831;I

Application led January 22, '1902. Serial No. 412,173.

Toi. all whom it may conce-rn;

Be it known that I, JOSEPH FREDERICK, a citizen of the United States, residing at Stroudsburg, in the county. of `Monroe'and State of Pennsylvania, have invented'a new and useful Pneumatic Hammer, of which the following` isa specification.

This inventionv relates to pneumatic tools otthat Igeneral class employed for cutting,I

calking or rivetingin metal or stone Work or .for luggingsand like purposes. T e principal object of the invention is to rately, all of the ports, both inlet and exhaust,

being undercontrol of the piston lor plunger;V

Afurther object of the invention is to form thepiston with a plurality of circumferential fluid receivinggrooves or ports which regissmall quantity of air to the opposite ends of the `cylinder for the purpose of cushioning the piston as the same reciprocates.

A further ob 'ect is to provide the inlet ort with amplurality of branch passages W ich open through the cylinder and are spaced a uniform distanceapart around the lston so thatthe. 'air will be directed lradial y of the .piston and "thus perfectly balance the same.

yA-ffstill'further object of the invention 1s generally to improve this class of devices so aste increase their utility, durabihty'and efliappended claims.

In the accompanylng drawings forming a jpart of this specification; Figure 1 is a sectional-elevation of a f pneumatic\ tool constructed in accordance with the present 1nven'tion, the pistonbeing shown starting on its 4working stroke. Fig. '2 is a sectional view jofftlie tool -with the handle removedshowing "the,4 piston ,starting on the return strdkel, a transverse sectlonal v iew taken'dn'the@line` of Fig. 1'. Fig. 4 1s a sectional view taken on the yline 4 4 of Fig. 1.

Fig; 5 lisa transverse'l sectional view .takenontheline i51-5 of, Fig. 1. A Fig. is a similar v iew taken,onfthej ofFigf 1. Flg.4 7 1s a V- Specification of Letters Patent. A'

split, extends over a ortion of the cylinder provided with a plurality of branc passages -22 preferably four in number, as shown, and vwhlch extend downwardly through the side through portsv23 and 24, there lbeing four Patented June 30, 1908.

I perspective view of. the plunger or piston removed. l

Similar numerals of reference indicate corresponding parts in all ot' the figures of the drawings. A

` The im' roved hammer forming the subject) matter -0 the present invention comprises a handle 10 having a spring closed valve 11 Which controls an inlet port 12 extending through the handle, as shown.

The handle is provid-ed with a'forwardly lprojecting neck 13 havin a threaded socket 14 for the reception of t e threaded end of the cylinder 15, while the'neck 13, which is pro er and is cla-mpc in place by a bolt '16. T e end of the cylinder o posite the handle 10 is provided with a suitaile tool socket 17 which receives the shank of a chisel, hammer, riveting or other tool illustrated at 1 8.

` The bore .19 of the cylinder is of uniform diameter throughout. and leading from this bore are exhaust ports and721, onenear the handle end and the other near the socket end of the cylinder, said exhaust o-rts passingdirectly through the-Wall f tli) 'ltlo piermit the escape of air or other actuating .The main air passage or inlet ort 12 is walls of the cylinder and are laced in communication With the bore o said cylinder orts 23 near the handle .of the cylinder, and our ports 24 near the tool socket end of the cylinder, all of said ports being under the control ofthe iston or lunger25. v

Attention is ere calle to the fact that the ports 23and 24. open into the cylinder around the piston 25 and are spaced a uniform distance a art so that air under the s'ame sure wil be directed radiall of the plston and thus perfectly balance t esame.

Near the handle end of thecylinder are arranged two orts 26 which communicate at one end wit the bore of the cylinder adjacent the handle thereof and at the 'opposite end communicate with the bore ofthe cylin-Q 105 der at a point inl alinement with the ports 23,'

the orts 26 constituting byfpas'ses through I whic the airmay iass from the port 23 to the handle end,of t e cylinder4 when the plse cyllnder res- ' 1 in order tofurnish the desired vpressure for the Working stroke.

At the tool socketend of the cylinder are arranged two by-pass ports 27, theouter. ends of which communicate with the outer end of the vcylinder at a point adjacent the socket 17, While the inner ends of said bypass ports communicate with the bore of the cylinder at a point in alinernent with the ports 24. l

The by. ass ports 27 permit the passage of air from t e ports 24 to the outer end of the cylinder4 when the piston is in extended osition, as best shown in Fig. 2 of the drawings.

- 30 which registers with the ports 23 and 24 when the piston is reciprocated and serves to permit a small portion of the air from the ports 22 and 24 to flow through the b y-passes 26 and 27 to the opposite ends of the cylinder 'thereby 'to form a cushion for the piston.

' -The grooves 30 not only allowsJ small quantity of air under pressure to pass to the o posite end of the cylinder for the. purpose of) 'forming a cushion at each end of the piston, but also forni afluid pressure packing i for the side walls of the piston.

In operationI the valve 11 being open and the piston in the position shown in Fig. 1 of the drawings air will flow through the port 15 and lluid passages 22 to the ports 23 into the chamber 29 and thence through' the by-. passes 26 to the head of the cylinder where-it aotson the piston or plunger and forces the latter outwardly to the position shown in Fig.- 2 of the drawings, the piston or plunger being forcibly driven against the tool. During the out stroke the plunger covers the ports 23 and uncovers the' exhaust port 20, the latter being opened just in advance of the. completion of the workingstroke of the piston so that the air in ther working end of -the'cylinder may escape.l .As the piston is forced iii contact with the tool 18 the adjacent a'nn'ulargroove 3() will register with the ports 23 and thus allow a portion of the air lto flow through the by-passes 26fto the haiidle end of the cylinder so as to give an addi tional impulse tothe piston, a port-lon of the air being retained in the groove 30 so as to forin a l'luid packing l'or the walls oit' the pis# ton,` in the manner before stated. When the piston moves to the opposite end of the cylinder and completes it-s working stroke the poi'ts 24 will be placed in commuiiication with the by-pass ports 27r and sut'- licient a'ir will pass to the ou'ter e'iid of thc cylinder to return the piston to the initial Y position showniuwjgfig. 1. As the piston is` by-paSSes 26 to the rear of the cylinder thus additional impulse to be impartedto the retracted or returned Lto normal position the adjacent groove 30 `will register with the port 23 and thus allow a portion of the air from the feed passage 12 to 'flow through the forming a cushion Jfor the piston, ai'ui'ther rearward movement of the piston uncovering the ports 23 andv jallowiiig'-tlie air to pass ythrough the passages 27 and move the valve in engagement with the' tool, in the manner before stated. It will thus be seen that the grooves 30 not' only permit a portion of the air to enter at the rear oef-the cylinder to 'form a' cushion for the piston but also permits an' piston after the latter had been started on its working stroke. lt will alsobe noted-that by forming' the inlet'port with a plurality of fluid passages arranged at equal distances apart on the interior of the cylinder an equal pressure is exertedon all sides ol thc piston so that the lat-ter is perfectly l al. anced and the ellicieiicy olf -the tool materially increased. Y

"liile there is shown and .described four the cylinder.. a `piston having a peripheral groove forming a port which co-acts with the inlet ports at both ends ol' the cylinder -for controlling the su )ply oll lluid, by-pass-ports leading 'from the inlet ports to the adjacent ends of the cylinder, and means l'or. permit- 105 ting the passage. o'l a portion ol the lluid through. thel by-pass ports alter the pis-ton has lstartedy on its working stroke.

2. In a pneumatic tool, a cylinder, a feed port having a plurality ol lhiid passages communicatiiig therewith and providediwith in let ports opening throughthe boreolthe cylinder at. `equal distances around the. 4wall thereof,- a piston mounted l'oi' reciprocation within the cvlinder and having an iii'lerniedi- 115 ate peripheral groove l'orniing a port which co-acts with the inlet ports l'or.controliii'ig the supply of lluid, and auxiliary grooves I'ormcd iii the piston one on each side ol' the intermediate. lgroove and, adapted .to register with permit thea-passage ol' air the inlet ports to' s of the. cylinder alii-i; the

to the adjacent en( `latter has started on its \\'orking stroke.

3. .ln a pneumatic tool, aevlinder, indes pendent ports arranged at cach end 'of the is?) cylinder, a piston mounted lor ieciprm-atmn. within the. cylinder and provided 'with'a" )ort which co-actswith the .inlet vpprts at oth 'ends of the 'cylinder 'lo'l controlling the vsupply of liuid, auxiliary portszirran'ged in 130 liuid ports openm'g into the cylinder atV each' the'piston and adapted to register with the inlet ports in the. cylinder thereby to permit,

the passage of air to the adjacentends of the cylinder to form a cushion on each stroke of the piston.

4. pneumatic tool including a cylinder Araving at -each end a by-pass port, both ends of which communicate with the bore of the cylinder, a feed port also communicating with the bore of the cylinder at'a point substantially in alincu'ient with the inlet end-of the by-pass port, a piston having a main port or passage for placing the inletport in communication with such by-pass port at each end of the piston stroke, and auxiliary ports formed in the piston and adapted to register with the inlet ports to admit a small quantity of air to flow to the adjacent end of the cylinder to form a cushion.

[n a pneumatic tool a cylinder having by-pass ports at each end thereof, feed ports conununicatingr with the bore of the cylinder at points in alinement with the inner ends of said by-pass ports, a handle member having a valve passage with which said feed ports communicate, a piston having a niain port or passage co-acting with the feed ports to permit the llow of air through the by-pass ports to the cylinder, auxiliary ports formed in the piston one on cach side of the main portand adapted to register with the inlet` ports of the cylinder to admit a small quantity of air to each end of the cylinder, and piston controlled exhaust ports leading from 'both ends o-t' the cylinder.

6. In a pneumatic tool, a cylinder, a han.

dle, a feed passage leading through the handle to the end of the cylinder, a piston in the presence mounted for reciprocation Within the cylinder, a plurality ofv branch passages communicating with the feed ort and provided with inlet ports opening t trough the walls of the cylinder at equal distances apart for directing the air radially of the iston, b ,-pass ports arranged at the end otthe cy inder, eac-h end of each by-'pass port communicating with the bore of the cylinder, the inner ends of the by-pass port being in transverse alinement with the feed port, there being a circumferential groove formed in the pislton that controls communication between the feed ports and by-pass ports, auxiliary grooves formed in the piston andadapted to register with the inlet ports thereby to admit a small quantity of air to the adjacent end of the cylinder, and independent piston controlled exhaust ports leading .from the opposite ends of the cylinder.

7., In a pneumatic tool, a cylinder, inlet ports arranged at each end 'of the cylinder, 'a piston for controlling the supply of fluid through said ports, bypass ports leading from the inlet ports to the adjacent ends of ythe cylinder', and a port formed in the piston and adapted to register with the inlet ports thereby to admit a relatively small charge of fluid through the byass )orts to the adjacent end ot the cyhm er alter the latter has started on its working stroke In testimonyY that I claim the foregoing as my own, I have hereto affixed my signature of two witnesses.

JOSEPH FREDERICK. Witnesses:

Ronirr II. ACE. 

